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astroengine writes "Astronomers have spotted something rather odd in the asteroid belt. It looks like a comet, but it's got a circular orbit, similar to an asteroid. Whether it's an asteroid or a comet, it has a long, comet-like tail, suggesting something is being vented into space. Some experts think it could be a very rare comet/asteroid hybrid being heated by the sun, but there's an even more exciting possibility: It could be the first ever observation of two asteroids colliding in the asteroid belt."

This is the first time I've heard it (or remember hearing it more likely)... it sounded to me like he was asking for the Captain to be killed.
(Wouldn't Spock be a fun character on Dexter turning into a homicidal vulcan psychopath? )

(Wouldn't Spock be a fun character on Dexter turning into a homicidal vulcan psychopath? )

[Excerpt from police interview]
Spock:
The captain has been bossing me around for years, putting me in harms way, and worst of all, trying to evoke responses from my human side... It was only logical that I put an end to this madness.

First time I heard that line I thought he was complaining about the beans.

Suit yourself, but somehow I enjoy thinking it's all about the heapin' helpin' of garbanzos Spock scoops up in the Enterprise cafeteria's salad bar. Vulcans just can't get enough of that Terran delicacy, smothered in Thousand Island dressing and a thick crust of black pepper. The first time Uhura and Sulu saw Spock doing that, they were like "whoa!", while Chekov was like "ay yay yay!".Scotty grimaced, stole a quick gulp of whiskey

It probably goes without saying that small accidents are more common than large ones. If women have more accidents in general, of course the number of small accidents is larger. You can only say "typically" like that because the numbers are so skewed. It has no bearing.

Quick disclaimer: I am a female, and I'm not trying to be judgmental or give off a feminist frame of mind.Observing sometimes as a pedestrian, I think women are far less likely to yeild than men. It's my theory that this is in part because in the back of a woman's brain there's this precedent set by manners--people hold doors open for women to go first all the time. Also, women are more social, so when they're driving, their minds are far more likely to be thinking about people, where they are going, when

Quick disclaimer: I am a female, and I'm not trying to be judgmental or give off a feminist frame of mind.Observing sometimes as a pedestrian, I think women are far less likely to yeild than men. It's my theory that this is in part because in the back of a woman's brain there's this precedent set by manners--people hold doors open for women to go first all the time. Also, women are more social, so when they're driving, their minds are far more likely to be thinking about people, where they are going, when they will get home, all of that, and not so much thinking about actually driving.

If the brain becomes better at something simply through hormonal changes, you would think there's something it becomes worse at at the same time. Apparently not for women who transcend these conventional stereotypes.

From the referenced article: "The hormones do have a downside. Some new mothers suffer from depression and in rare cases, even psychosis. Research at Tufts University and elsewhere suggests some potential animal models and endocrinological mechanisms for postpartum mental distress, broadly defined. It suggests that hormones are to blame: an acute pull-back, addict-like, from the rich concentrations of steroids that characterize pregnancy may play a role in the severity of postpartum reactions."

They don't generally collide!? What about when the Millenium Falcon hid in one? Does that mean the Empire Strikes Back was all made up? Next thing you're going to tell me that there aren't giant space eels living in the bigger rocks. (Places fingers in ears and sings loudly Star Wars theme song)

Relax! That was Long Ago in a Galaxy Far, Far Away. Our asteroid belt is boring, with every rock more or less tidally locked to each other. Their asteroid belt is dynamic and exciting, and filled with hungry, hungry space eels.

Our asteroid belt is boring, with every rock more or less tidally locked to each other.

It's also a lot sparser than a lot of people realize--enormously more empty than any representation you see on film, TV or video games. You could fly through it and never see an asteroid with the naked eye except as a point of light.

If the observed one keeps doing a circular orbit, then probably the other didnt had mass enough to move it, so probably is small enough to not worry about it, even if by extremely low odds is coming here.

If the scientists are coming up with such dull scenarios, how can they motivate the youngsters into science?

It is well known that when rebels jump into hyperspace to escape the pursuing imperial battle cruisers, they might pop out in an asteroid belt. But most people think it is always possible to negotiate the craft around it and escape. Such false notions are strengthened by reports of more manuevrable craft deliberately entering asteroid belts to escape pursuit. But they don't always succeed and they

What exactly do they mean by hyper-velocity? Are we witnessing a collision between two objects whose velocities add up to more than the speed of light? Eg. one coming in from the left at 3/4c and one coming in from the left at 3/4c.

The term hypervelocity usually refers to a very high velocity, approximately over 3,000 meters per second (6,700 mph, 11,000 km/h, 10,000 ft/s, or Mach 8.8). In particular, it refers to velocities so high that the strength of materials upon impact is very small compared to inertial stresses. Thus, even metals behave like fluids under hypervelocity impact. Extreme hypervelocity results in vaporization of the impactor and target.

Only in Newtonian mechanics. However, if the objects' velocities are so fast that they would sum to more than the speed of light, then you need to use relativity. In no reference frame does the velocity of one relative to the other exceed c. I'm afraid I'm too lazy to look up the formula. The shelf with all my physics books on it must be 10 feet away from me (although at 0.8c it's only 6 feet).

>>However, if the objects' velocities are so fast that they would sum to more than the speed of light, then you need to use relativity.

Mr. Pedantic: You always have to use relativity, not just when combined vectors exceed c. Realistically, of course, you only have to start worrying about it when velocity starts exceeding some sizeable fraction of c (but still well before > c in Newtonian physics).

Humans are good at context recognition. We can often gather information when data is missing or incomplete as much of human speech is effectively redundant. Thus, we can often complete a .
In this case, the incomplete sentence made the headline shorter and made it very clear what was being communicated. The headline communicated that there may have been an asteroid collision but that scientists were very unsure. Headlines frequently use sentence fragments so we can quickly scan over them and see if we are i

We spend peanuts on detecting potential collisions that could be the cause of the next extinction event. Mark my words, there'll be more money spent on earthquake analysis for Haiti and other "sensational" causes than will be spent on detecting PHOs (potentially hazardous objects) in the next 10 years. I am not denigrating the need to spend money on Haiti - that's a tragedy for sure - but when you look at how reactive we are with public money (New Orleans, anyone? Despite warnings, no one saw this coming?) when a much smaller amount spent up-front would potentially save not just a lot more lives but a lot more money....if better building codes had been in force in Haiti - how many more people would have survived? How much money would have been saved?

I despair for our race. If we saw a dinosaur killer coming and had a program in place already we could probably survive it. Asteroids move slowly but are heavy and require a lot of time/energy to deflect so we would see them early and be able to react...comets move much, much faster but are lighter so presumably if we had the detection gear and a few mass drivers in space already, we could deal with it in a safe time frame.

So give us our Haiti or Katrina from space, please. Make it hurt but not too much - just enough to wake up the people handing out government cash.

Scenario 1: Asteroid strike. I defer to NASA JPL [nasa.gov], the Tunguska event (100-meter class = ~ 15 mil tons TNT) asteroid occurs once or twice / 1000 years. A 1000-meter class is 1 in 15 million years. An 8000-meter class (dinosaur killer) is 1 in 50-100 million years.

Scenario 2: Earthquake. San Francisco [usgs.gov] has an annual forecast of earthquake probabilities, and they predict a 68% probability of a 6.7 Magnitude or greater in the next 30 years. Wikipedia [wikipedia.org] gives a probability scale for earthquakes, where a Magnitude 7 (similar to what struke Haiti) occurs 18 / year. A single 6.7 earthquake (P = 120/year) is equivalent to 16 kilotons of energy, or about 1 Tungaska event (P = 0.004/year).

Given the disparity in the probability of asteroid strikes (on populated areas, no less) vs earthquakes, it should be no surprise that the world governments believe money is better spent on earthquake prediction and evacuation relief, not on asteroid strike detection. The "bang for the buck" is clearly higher in earthquake spending.

"We cannot rely on statistics alone to protect us from catastrophe; such a strategy is like refusing to buy fire insurance because blazes are infrequent. Our country simply cannot afford to wait for the first modern occurrence of a devastating NEO impact before taking steps to adequately address this threat. We may not have the luxury of a second chance, for time is not necessarily on our side. If we do not act now, and w

Given the disparity in the probability of asteroid strikes (on populated areas, no less) vs earthquakes, it should be no surprise that the world governments believe money is better spent on earthquake prediction and evacuation relief, not on asteroid strike detection. The "bang for the buck" is clearly higher in earthquake spending.

1. An earthquake affects a relatively small population.

2. A single dinosaur killer could wipe out humanity.

3. Probability for all these events approaches 1 as time goes on.

In light of the above your "bang for buck" argument is silly. It's like counting the pennies while sitting on the railroad track with your back turned to a huge locomotive with blaring sirens that's about to hit you at 100km/hr and arguing that it costs too much to turn around and look at how close it is, never mind get off your ass and out of the way of the train.

And what exactly do you suppose we puny humans can do about that "huge locomotive with blaring sirens that's about to hit [us]"? We can neither deflect the "locomotive" (your "dinosaur killer"), nor can we get out of the way (move the whole planet).

Not like there's anything we can do about preventing earthquakes either.

But even if we had the ability, do we have the wherewithal to actually do anything about either asteroids or earthquakes? We're demonstrating how good we are about ignoring the future and

And what exactly do you suppose we puny humans can do about that "huge locomotive with blaring sirens that's about to hit [us]"? We can neither deflect the "locomotive" (your "dinosaur killer"), nor can we get out of the way (move the whole planet).

We can't deflect it in the stupid way portrayed in movies, but we may well be able to change it's trajectory. How do we know? Have we spent any significant time or resources trying to find a way? Your defeatist attitude is awful, and we'd never have survived as

I don't think the "bang for your buck" argument is silly because it's an incredibly common fallacy that no doubt affects the people making the decisions as well. The fact that it's fallacious makes it no less a motivating factor for those who control our money.

The mods sometimes do mod a good joke "Informative" or "Insightful" to add more fun to it, in this case suggesting the classic Asteroids game physics were real. I'm not sure who is "Clueless" or "Humorless" in this case.

Actually, they mostly do it to reward the poster since Funny mods don't increase karma, but Informative or Insightful mods do. Something that's modded to +5 Funny and then modded Overrated a few times will even burn the poster's karma. But yes, it's also humorous in most cases.

Think about that for a minute, and you'll realize why it hasn't been done.

You'd fly for a long, long time in mostly empty space. When you found an asteroid, most of them would be too large for any conceivable weapon to significantly affect, and the smaller ones wouldn't just break in half, they'd break into hundreds or thousands of smaller chunks, traveling in all directions at high speeds. And those saucers? You'd never even see them, because they'd engage you at a range of several light seconds with beam

There's a reason you don't normally see icy bodies in circular orbits in the asteroid belt: they'd be blown clean of the ice within a fairly short period of time, astronomically speaking. that's what the tail consists of, dust embedded in the ice being released as the ice sublimes. Which means that the ice here has to have been exposed fairly recently.